Retainer assembly for a fuze



Oct. 21, 1958 s, p, o ow -rz 2,856,855

RETAINER ASSEMBLY F OR A FUZE' Filed Oct.- 13, 1955 INVENTOR.

5 amuel D.Hnruwi cz 2 BY ATTDRIVEZ' E1.

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RETAINER ASSEMBLY FOR A FUZE Samuel D. Horowitz, Tonawanda, N. Y.assignor to the vUnited States of America as represented by theSecretary of the Army Application October 13, 1955, Serial No. 540,361 3Claims. (Cl. 102-79 This invention relates to a centrifugally-armed,impact type fuze and, more particularly, to a fuze of this type isslidably mounted in the bore of barrel 18 and is provided at itsrearward end with a striker 22 which nestles in bore 13 when the fuze isin unarmed relation to lock the rotor in safe position. The pin also hasa mushroomshaped head 23 at its forward portion as clearly shown uponFigs. 1 and 5. The rearward face of head 23 is con-' cave as at 31 andis held against the forward planar face 16 of the retainer body 14, whenthe fuze is in unarmed relation, by a cross pin or rider 24diametrically received in the rearward portion of firing pin shank 21and which contacts the helical or cammed edges 19 of barrel 18.

which is positively maintained in safe or unarmed posi tion under allconditions of handling and is armed in an equally positive manner onlyafter the projectile carrying the fuze has attained maximum spin infiring and is well along on its trajectory, and free and clear of thegun.

The principal object of the invention is to provide a fuze that is safefor handling, transporting, and ramming,

' that is bore safe, armed only after the projectile is in free flightand relatively simple and easy to fabricate and assemble.

'The specific nature of the invention as well as other objects andadvantages thereof, will clearly appear from a description of apreferred embodiment as shown in the accompanying drawings in which:

Fig. l is a longitudinal section to an enlarged scale taken throughajfuze constructed in accordance with the invention, v

Fig. 2 is a cross section taken along line 2-2 of Fig. 1 and looking inthe direction of the arrows,

Fig. 3 is a cross section taken along line 3-3 of Fig. l I

and looking in the direction of the arrows,

Fig- 4 is a perspective view of a retaining barrel hellx or cam forminga component of the retainer assembly,

Fig. 5 is a similar View tion.

Referring more particularly to the drawing, wherein like referencecharacters designate like or corresponding parts throughout thedifferent views, reference numeral 1 designates generally a nose portionof a projectile having a fuze body designated generally by 2 attachedthereto. The nose portion of projectile 1 contains a bursting charge 3and is counterbored as at 4 and internally threaded at 5 to receive thebase portion 6 of fuze body 2 which is externally threaded as at 7. Fuze2 is bored axially as at 9 to receive a booster 10, and counterbored asat 8 to receive arming mechanism.

The rearward portion of bore 8 is generally hemispherical and houses anarming rotor or ball 11 adapted for rotation therein. Rotor 11 has adiametral bore housing a detonator 12 therein and is bored radially at apoint 13 on its surface oifset from the diametral axis of detonator 12.

Fixed to the base portion 6 by suitable means such as staking at 6a, isan axially disposed retainer body 14 having a concave rearward face 15receiving the forward portion of rotor 11, and a forward planar face 16.Retainer body 14 is provided with an axial bore 17 to receive a' tubularretainer barrel helix or sleeve 18 as best seen in Fig. 1. Barrel 18 isprovided with a pair of longitudinal diametrically disposed slotsopening through its rearward edge each having one corresponding edge inthe form of a helix l9 and a splined or serrated forward surface 20having a press fit within bore 17 of retainer body 14 to preventrotation of the barrel when inserted into bore 17. A firing pincomprising a shank 21 ofthe firing pin of the inven- Rotation of thefiring pin is prevented by an arming spring 25 which has a semicircularportion received in an annular groove 26 in the base of the retainerbody 14 and integral forwardly protruding prongs 32 which lie in a pairof diametrically disposed longitudinally-extending notches 27 cut in theretainer body 14, as best seen in Fig. l. The prongs 32 extend forwardlybeyond the body 14 and their free ends engage in a pair of diametricallydisposed notches 28 formed in the outer peripheral surface of head 23.See Fig. 5. A number of arming balls 29 shown as three in number, arereceived in the space formed by the planar face 16 of the retainer bodyand the concave rearward face of the head 23.

A cover or windshield 30 is provided to protect the nose portion of thefuze and to provide access to the operating elements.

The operation of the fuze is as follows:

As illustrated in Fig. 1, the fuze is shown unarmed. In this position,the cross pin 24 of firing pin shank 21 lies at the base of the barrel18 in contact with the rear portion of the helical edges 19 and ismaintained in this position by'engagement of the spring prongs 32 innotches 28 of head 23. This holds the striker 22 in the bore 13 of therotor 11, and until it is removed therefrom, the fuze is in an unarmedor safe condition and will withstand any linear acceleration ordeceleration i. e. jolt, drop, ramming, etc.

Upon being subjected to annular acceleration, in firing, centrifugalforce -will cause the prongs 32 of arming spring 25 to move radiallyoutward of slots 28 in head 23, thus rendering the firing pin 21 capableof revolving in either direction and moving forward to withdraw striker22 from bore 13 of rotor ball 11.

Angular acceleration due to clockwise spin in the model shown, willcause the projectile 1, fuze 2, retainer body 14, and barrel 18 to lockup more securely on the firing pin with the result that the pin 21,despite release by spring prongs 32, will be momentarily held with itsstriker 22 in bore 13 to thereby guarantee bore safety.

Upon contacting the turbulence caused by the propellent gases and airpushed out in front of the projectile at the muzzle of the weapon, theaforesaid lock up is neutralized or broken and the mechanism is readyfor arming.

Centrifugal force acting upon arming balls 29 will cause them to moveoutward against the inclined under:

surface 31 of the head portion 23 thus positively camming" the firingpin forwardly. The balls 29 then fly free of the assembly and into thespace formed between the retainer body 14 and cover 30 where they areheld.

Arming delay is achieved in this lapse of time between the entry of thefuze and projectile into the turbulent field and the time necessary forthe arming balls 29 to apply their full force against the cammingsurface 31 of the firing pin head 23 and the resistance of the pin 24against the helical edges 19 of the barrel 18, demanding angular as wellas linear movement of the firing pin in order to free rotor 11.

As this is accomplished, the striker 22 of the firing pin 21 iswithdrawn from the bore 13 in the rotor 11, allow- (maintained incontact with the cover 3%) upon contact with a target, isrdrivenrearward, causing the striker 22 to penetrate the detonator llandinitiate the detonator and the main charge 3 of the projectile.

It'is' apparent from the foregoing, that a novel and highly efficientfuze has been designed which accomplishes the objects previously stated.The elements comprising thezfuze are relativelyeasy to fabricate andassemble andthe desired delayed-action arming, is positive and certain.

Whilea preferred form of invention has been shown and described, variousmodifications and substitutions of equivalents will occur .to thoseskilled in the art after a study'of'the foregoing disclosure. Hence, thedisclosures should be taken in an illustrative rather than a limitingsense, and it is my desire and intention to reserve all'inodificationswithin the scope of the subjoined claims.

Having fully disclosed the invention, what is claimed and desired tosecure by Letters Patent is: l

1. In a centrifugally armed fuze, a fuze body having a longitudinal axisof symmetry, a rotor journaled in said body for rotation froma firstsafe position to a second armedposition, means fixed with said bodyforwardly of said rotor and defining a rearwardly-facing camming edgehelical about said axis forwardly in the direction of spin of said fuzein firing, a firing pin carried by said body coaxial of said axis andtranslatable forwardly from a first position engaging and holding saidrotor in safe position, to a second position freeing said rotor forrotation to armed position, said pin including an enlarged head having arearwardly-facing forwardly and inwardly inclined cam surface, meansfixed with said body and defining'a forwardly-facing surface formingwith said cam surfaceanannular chamber, at least one ball positioned insaid chamber and acting to cam said firing pin forwardly in response toradially outward motion of said ball, and a cam rider fixed with saidfiring pin and engaging said helical edge.

2. A centrifugally armed impact fuze comprising, a

fuze body having a central longitudinal axis, a rotor jourl '4 lockingsaid rotor, forwardly to a position releasing the same, said firing pinhaving an enlarged head, means fixed with said body and defining withsaid head an annular chamber of decreasing dimension in the axialdirection radially outwardly of said axis, a plurality of rollingelements mounted insaid chamber, means constraining said firing pin toinitially rotate as a unit with said body and releasable in response tocentrifugalbforce, and a rider fixed with said firing pin and engagingsaid helical edge.

in a ccntrifugally-armed point detonating impact fuze, a fuze body,having a longitudinal axis of 'symmetry, a ball rotor journaled inasphericaltcavity incsaid body for rotation under centrifugal. force froma safe to an armed position, a tubularsleeve fixed withsaid bodyforwardly of said rotor along said axisand having diametrically-opposedcut-outs in its side walls defining first and second duplicate helicalcamming edges, avfiringpin slidable axially in said sleeve fromarearward position engaging and holding said rotor in safeposition to aforward position releasing said. rotor for: rotation to armed position,a pair of cam riders fixedin diametrically ,op: posite positions on.said pin, each engaging a respective camming edge, said pin includingahead having a rear- 'wardly-facing, outwardly and rearwardly disposedcam surface of revolution, about said axis, means fixedwith saidbodydefining a forward planar face transversely of saidlaxis anddefining with the cam surface of said head, an annular chamber, aplurality of balls confined in said chamber and operable in response tocentrifugal force, to cam said pinto forward position, and a springfixed with. said head sand having, diametrally-disposed prongs extendingforwardly with their endsseated in respective notches in said head, saidprongs. initially holding said firing pin in rearward POSltiOIlfllldcausing thesame to rotate as a unit with said body but releasing thesame under centrifugal force of -rotation about said axis.

References Cited in the file of this patent UNITED STATES PATENTS1,313,930 Taylor Aug. 26, 1919 1,316,131 Baldwin Sept. 16, 19192,446,019 Nichols July 27, 1948 2,595,757 Brandt i May 6, 1952 2,790,390Baker Apr. 30, 1957 FOREIGN PATENTS Sweden Aug. 27,

